Buttonhole sewing machine



y 6, 1931- E. B. ALLEN 'BUTTONHOLE SEWING llACI-IINE Filed Nov. 29, 19278 Sheets-Sheet l INVENTOR zo ud a.

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WITNESZES ATTORN EY May 26, 1931. E. B. ALLEN BUTTONHOLE SEWING MACHINEFiled Nov. 29, 1927 8 Sheets-Sheet 2 U a W y 931. E.YB. ALLEN 1,807,577

BUTTONHOLE sswme mum 4 Filed Nov. 29. 1927 a Sheets-Sheet s f INVENTOR 4m 5 46 WITNESS? 1 Q M ATTORNEY May 26, 1931. B. ALLEN 1,807,577

' I BUTTONHOLE SEWING MACHINE Filed NOV: 29. 1927 8 Sheets-Sheet 4.

wl mzssgg Y v 7? i ATTORNEY May 26, 1931. E. B. ALLEN 1,307,577

BUTTONHQLE SEWING IACHINE Filed Nov. 29, 1927 a Sheets-Sheet 5 7 May 26,1931. 7

E. B. ALLEN BUTTONHOLE SEWING MACHINE 8 Sheets-Sheet 6 Filed Nov. 29,1927 ATTORNEY y 1931? 7 E. B. ALLEN 1,807,577

' BUTTONHOLE SEWING MACHINE Filed Nov. 29, 1927 8 Sheets-Sheet '7 BLQ 1*l 150 l w A l 100- v a? INVENTOR m 7, mus? I BY k AI'IITORNEY y .1931,E. B. ALLEN 'BUTTONHOLE SEWING ncama Filed Nov. 29, 1927 8 Sheets-Sheet8 INVENTOR- w flab ATTORNEY Patented May 26, 1931 I UNITED STATES EDWARDB. ALLEN, OF NEWI'OWN, CONNECTICUT, ASSIGNOR TO THE SINGER MANU-FACTUBJING COMPANY, OF ELIZABETH NEW JERSEY, A CORPORATION OF NEW JERSEYBUTTONHOLE SEWING MACHINE Application filed November 29, 1927.

This invention has for an object to provide improved control means forvarying the sequence of operations of several independent groups ofmechanism in an organized buttonhole sewing machine, and particularly toprovide for the invariable automatic opening and unspreading of thework-clamp at the close of the button-hole producing cycle regardless ofthe particular sequence of operations of the previously actingmechanisms.

To secure the best quality of work, it is desirable that thebuttonhole-slit be cut first and then overseamed, so that the stitcheswill cover the cut edges of the material, but with loosely woven or thinfabrics it is often necessary to change the order of the cutting andstitching operations, so that a sufficiently firm foundation may be hadfor reception of the oversea-m; the buttonhole slit being out after theoverseam is completed.

In a modern automatic buttonhole sewing machine having, in addition tothe buttonhole-cutting and stitch-forming mechanisms, clamp-closingmechanism, clampspreading mechanism, rapid-feed mechanism for effectinga rapid relative shift of the work-clamp and stitch-forming mechanismsinto and out of sewing relation, clamp-opening mechanism andclamp-unspreading mechanism, the changing of the sequence or order ofoperation of the buttonhole-cutting and stitching mechanismsnecessitates the provision of a system of control devices affecting thevarious other. mechanisms, in order that they may automatically followone another in the desired order. It is with an improved system ofcontrol devices that the present invention is particularly concerned.

To the attainment of the ends in view the clamp opening and unspreadingmechanism is provided with control means connected to the means forcontrolling the order of the buttonhole cutting and stitchingoperations, so that the work-clamp will be automatically opened andunspread regardless of whether the machine is set to cut the buttonholebefore or after stitching.

1n the accompanying drawings, Fig. 1 is a right side elevation of abuttonhole sewing Serial No. 236,402.

machine embodying the invention. Fig. 2 is a left side elevation of themachine. Fig. 4-5 is a horizontal section through the bracketarmstandard of the machine, showing the machine bed in plan. Fig. 4 is abottom plan view of the machine. Fig. 5 is a rear-cnd elevation. Fig. 6is a detached detail view of certain parts of the control mechanismshown in Fig. 5. Fig. 7 is a front-end elevation of the machine. Fig. 8is a view of the selective control mechanism shown in F 1. Fig. 9 is afragmentary transverse section through the machine bed showing detailsof the rapidfeed control mechanism. Fig. 10 is a sectional view on theline 99, Fig. 9. Fig. 11 is a section on the line 1111, Fig. 8. Fig. 12is a detached plan view of certain parts of the control mechanism shownin Fig. 3. Fig. 13 is a section on the line 1313, Fig. 2. Fig. 14 is asection on the line 1414, Fig 2. Fig. 15 is a disassembled perspectiveView of the cam-member and its supporting shaft shown in Fig. 14. Fig.16 is an elevation from the inside of the machine, looking at certainparts of the control mechanism in the reverse direction to that shown inFigs. 1 and 8. Fig. 17 is a detail view of certain parts shown in Fig.16. Fig. 18 is a fragmentary vertical transverse section through theright side-wall of the machine bed on the line 1818, Fig. 8.

*ig. 19 is a section on the line 19-19, Fig. 0. Fig. 20 is a plan viewof the parts shown in Figs. 18 and 19. Fig. 21 is a perspective view ofone of the control levers shown in Figs. 18 and 19, and Fig. 22 is aView of the tension-release mechanism. 1

As the present invention'has to do wi a. novel control means for varyingthe sequence of operations of several independent groups of mechanism inan organized buttonhoic sewing machine, which groups of mechanism areold in the art, a brief description will first be given of the severalold mechanisms followed by a description of the novel control means forvarying their sequence of operation.

According tothe preferred embodiment of the invention illustrated, themachine is constructed with a frame including a hollow rectangular bed 1from which rises the standsewing saaft.

ard 2 of the bracket-arm 3 terminating in the head 4.

The stitch-forming mechanism, its stopmotion device and the controllingmeans therefor are constructed substantially in accordance with thedisclosure of the Allen Patent No. 15,324, reissued April 4, 1922, andthe Allen et al., Patent No. 1,372,473, of March 22, 1921. Suchmechanism comprises the usual needle 5 carried by the reciprocatory androtary needle-bar 6 and the underthread mechanism 7 carried by therotary turret 8. The needle and under-thread mechanism are given theirstitch-forming movements by the usual connections with the main sewingshaft 9, as shown in said reissued patent, except for a slight change inthe mechanism for reciprocating the central looper-bar 8'. In thepresent machine the looper-bar 8 is reciprocated by a link-connection 8with a lever-arm 8 which is rigid with the lever-arm 8 fulcrnmed on thestud 8. The lever-arm 8 has a follower 8 entering a cam-groove 8 in thedisk 0*- fiiied to the main-shaft 9. As the specific character of theactuating mechanism for the stitchforming devices has nothing to do withthe present invention, further description thereof is deemedunnecessary. The period of action of the stitch-forming mechanism iscontrolled by means of the usual stop-motion device comprising thestop-motion lever 10 fixed to the pivot-shaft 11, journaled in bracket12 fixed to the machine frame. The stop-motion lever 10 carries adownwardly springpressed locking tooth 13 which cooperates with thewell-known stopping and clutch-controlling cam 14 on the main sewingshaft 9 on which is the constantly running belt-pulley 15. A tilting ofthe stopmotion lever 10 in a direction to compress the spring 16withdraws the locking tooth 13 from the stop-notch. 14' in the cam 14and establishes driving relation between the pulley and sewing shaft 9.The return of the stop-motion lever 10, under the influence of thespring 16, to the position shown in Fig. 1, effects disengagement of thesewing shaft 9 from the driving pulley 15. As the tooth 13, which isfirst elevated by the rise 14, Fig. 5, of the cam 14, drops into thestop-notch 14 in the latter, the shaft 9 is brought to a. positive stepin a predetermined position with the needle 5 out of the work.

The operation of the stop-motion lever 10 is controlled by thepattern-cam 17, Fig. 2, on the cross-shaft 18, which cam acts upon thefollower lever 19 connected by L118 link 29 to the arm 21 on thestop-motion lever pivot-shaft 11. When, in the turning movement of thecross-shaft 18, the cam ris 22 of the pattern-cam 17 engages thefollower-nose 23 of the lever 19, it tilts the stop-motion lever 10 torunning position and starts the lVhen the drop-off shoulder 24 of thecam 17 passes the nose 23, the spring 16 is free to shift thestop-motion lever ll) to the position shown in the drawings, to stop thesewing shaft.

The work-clamp comprises the lower clamp-plates 25 and upper clamp feet26 which are mounted in the usual manner for movement over the machinebed to carry the work from buttonhole cutting or starting position tostitching position, thence in a path to place the stitches around thebutton hole, and lastly back to buttonhole cutting or starting position.These movements are derived from the usual feed-wheel 27 andpattern-wheel 17 through the usual connections, such as shown in saidreissued patent. The feed-wheel 27 is connected by bevel-gearing 28 tothe cross-shaft 18 which carries the pattern-wheel 17, so that both thefeed-wheel and the pattern-wheel must run together. During the portionof the cycle when the stitch-forming mechanism is active, the feedwheelis driven in step-by-step fashion from the sewing shaft 9 through theusual pin and star-wheel drive 29, Fig. 4, and gearing train 30. Duringthe portions of the cycle immediately preceding and following the sewingperiod, when the work-clamp is being carried to and away from sewingposition, the feedwheel is driven at a continuous and more rapid speedfrom the rapid-feed shaft 31 which is driven continuously by theconstantly running pulley 15 through the connecting train of gears 32.

The rapid feed-shaft 31 has fixed thereto a worm 33 which drives thegear 34- fixed to the live element of a clutch 35, the driven element 35of which is lined to the cross-shaft 18. The clutch controlled by thesliding movement of the cone 36 on the shaft 18; driving relation beingestablished between the shafts 31 and 18 when the cone 36 is moved awayfrom the clutch 35 and interrupted when the cone is shifted toward theclutch. The shifting of the cone is effected by means of the arm 37 onthe slidably mounted clutch controlling shaft 38, all of the foregoingmechanism being well known and disclosed, for example, in said reissuedpatent.

The rapid-feed-shaft 31 has formed therein a crank 39, Fig. 9, embracedby the forked arm 40 of a bell-crank-lever, the other arm 41 of whichhas pivotally connected thereto a push-bar 4-2 formed in its upper edgewith a notch affording an abrupt shoulder -43 and an inclined shoulder44. This bar 42, which is constantly reciprocated by the shaft 3]., isheld in its idle position, Figs. 9 and 10, by a latch 45 pivoted at 46on the machine frame. The spring 47 secured to the outer end of the bar4-2 tends at all times to pull the bar 42 upwardly against theoverhanging finger 45 of the latch. The latch 45 is formed with a slot48 which receives a pin 49 on the arm 50 fixed to the rapid-feedstarting rock-shaft 51. It will be understood that when the shaft 51 isrocked, the latch is swung to the right, Fig. 10, releasing theconstantly reciprocating push-bar 42 which is swung up- V wardly by thespring 47, Fig. 9, until the notch between the shoulders 43, embracesthe pin 52 on the pid-feed clutch-controlling shaft 88. Upon the nextreciprocating impulse of the bar 42 to the right, Fig. 9, the abruptshoulder 43 engages the pin 52 and pushes the bar 38 endwise to throw inthe rapid-feed-clutch. The bar 38 is retained in clutching position bythe upwardly springinfluenced latch-lever 58 which is fulcrumed at 54independently of the bell-crank-lever 40, 41 and carries a shoulderedpiece which engages and retains the finger 56 carried by the bar 38. Onthe return endwise impulse of the bar 42 to the left, Fig. 9, theinclined shoulder 44 engages the pin 52 and depresses the bar 42sufiiciently to be re-engaged by the overhanging finger 45' of the latch45 and held in idle position. Thus, a rocking impulse of the shaft 51throws into action the mechanism for rapidly driving the feedwieel. Thethrowing out of action of this mechanism is accomplished bytrippingpoints 57, 58 on the inner face of the patternwheel 17. Thesetripping-points rock the lever 59, the forked end of which embraces theend of the latch lever 53and pulls the latter downwardly, thus causingthe shoulder 55 to release the finger 56, whereupon the shaft 88' isreturned to the rapid-feed declutching position by action of the spring38, Fig. 4. The tripping-point 57 throws out the rapid-feed after thework-clamp has been moved from starting position to sewing position andthe tripping-point 58 again throws out the rapid-feed after thework-clamp has been returned from stitching to starting p0sition nearthe close of the cycle of operations.

The work-clamping feet 26 are depressed to grip the work by clock-wiserocking movement of the connected shaft-sections 61, Fig. 1, suchrocking movement being effected by the downward movement of the roller62 carried by the forwardly extending arm 68 of the three-armedclamp-closing rock-lever, 63, 64, 65, fulcrumed at 66 on the machineframe; the roller 62 engaging the arm 66 fixed to one of the rock-shaftsections 61.

The three-armed clamp-closing lever 63, 64, is similar in function toand is controlled in the same manner as that disclosed in said reissuedpatent. When the machine is started, the clamp-closing lever is given asingle complete to-and-fro movement by means of a cam-groove 67 in theinner face of the continuously driven belt-pulley 68. The rearwardlyextending arm 64 of the clampclosing lever carries the endwise movablefollower-pin 69 which is held in ejected position, out of engagementwith the cam-groove 67, by the latch 70 pivoted at.71 to the standard 2.This latch is swung to the right, Fig. 1, to release the pin 69 by theaction of the open tor in depressing the forward end of the startinglever 72, the rearward end of which engages a lever 73 which, in turn,is connected to the vertical rod 74 the upper end of which is connectedto the bell-crank-lever 75, 76 also fulcrumed at 71. The arm 76 carriesa pivoted catch 77 which engages the pin 78 on the latch 7 O andwithdraws the latter from the notch 69, Fig. 3, in the pin 69 which isthereupon urged by the spring 78, Fig. 5, into the actuating cam-groove67. After one co-andfro movement of the three-armed-lever 63, 64, 65,the pin 69 is ejected from the camgroove 67 and latched in ejectedposition.

The first movement of the three-armed lever is a counter-clockwisemovement, Fig. 1, which closes the work-clamp. The work is spread by theaction of a cam-bar 7 9 which is pivoted at 80 on the lever 80*, Fig.16, the curved lower end of which carries a follower roll 80 in positionto beactuated by a cam 80 on the vertical gear 28 early in the rapidfeedof the work-clamp from initial or button hole cutting position to sewingposition. The bar 79 shifts the operating lever 81 of the usualclamp-spreading toggle-mechanism 82, described in said reissued patent,thus el'lecting the spreading of the worlcclamp.

The buttonhole cutting mechanism is sub stantially the same as thatdisclosed in said reissued patent and comprises the upper and lowercutter levers 83, 84 which are pivoted at 85 on the cutter-carrierfulcrum-block 86 1 which slides in ways formed longitudinally of themachine bed. The cutter-levers and carrier-block are operativelyconnected as usual with the cutter-shaft 87, the action of which isgoverned by a one-rotation clutchw device controlled by thecutter-clutch controlling lever 88 which is fulcrumed at 89 on themachine frame. The buttonhole cutter mechanism, cutter-clutch, andcontrolling lever 88 are well known and are disclosed in said reissuedpatent and in the Allen Patent No. 1,548,815 of August 11, 1925. Whenthe lever 88 is shifted inwardly or away from the driven cutter-clutchdisk 90, the coupling tooth 91 is released and slides outwardly underthe influence of the spring 92 into en ga gement with one of the drivingteeth 93, Fig. 5, of the driving clutch-member which is formed as a partof the continuously driven beitpulley 68. At the end of one revolutionof the cutter-shaft 87, the tooth 91 is withdrawn from the driving toothand the disk brought to a positive stop.

At the close of a cycle of operations the work clamp is automaticallyopened and unspread; the opening being accomplished by the bar 95 whichis pivoted at 96 to the upright arm 97 of a bell-crank-lever 97, 98fulcrumed at 99 on the machine frame. A rocking impulse ofbell-crank-lever 97, 98 projects the front end of the rod intoengagement with the upstanding arm fixed to the work-clamp rock-shaftsection 61, tilting such arm forward and opening the workclamp. Previousto engagement of the bar 95 with the arm 100, however, the tripper 101on the rod 95 engages the tail 102 of the latchlever 103 which locks thework-clamp in closed position by engagement with the tail 104 of the arm100, as shown in dotted lines, Fig. 2. On the forward movement of therod 95 the arm 105 fixed to such rod engages the lever 106 of theclamp-spreading toggle mechanism and shifts such lever to the positionshown in Fig. 3, breaking the toggle and unspreading the work-clamp.

T he means for rotating the needle and looper mechanisms in sewingaround theeyelet-end of a buttonhole and for reversely rotating suchmechanisms after the sewing is completed, to return them to initialposition are constructed substantially in accordance with the disclosureof said reissued patent and comprise the usual sector gear levers 107,108, Fig. 2, and their respective link connections 109, 110, with arms111, 112, on the vertical shaft 113; the arm 112 having a followerroll114 which enters the cam-groove 115 in the feed-wheel 27.

All of the foregoing mechanisms are old in the art and disclosed in thecited prior patents. There now follows a description of the novelselective control mechanism for varying the sequence of automaticoperation of such mechanisms to produce the two distinct types ofbuttonhole contemplated, (a), a cut-first buttonhole, the slit of whichis out before the overseam is sewn, and (b), a cutafter buttonhole, theslit of which is out after the overseain is sewn.

Fnlcrumed at the right-hand side of the machine on the pivot screw 116is the selec tive master control lever 117 to the lower end of which issecured by the screw 118, the leafspring arm 119 vertically slotted at120 to embrace the screw 121 fixed to the arm 117. The head of the screw121 is spaced out-wardly from the spring arm 119 and limits the outwardmovement of the latter. The arm 119 is vertically slotted at 122 toembrace the grooved outer end of ti e latch-pin 123 slidably mounted inthe boss 124 fixed to the arm 117; the pin 123 being in position toenter one or the other of the holes 125, 126 in the guard 127 having arigid arm 128, Fig. 1, whereby it is fixed by the screw 129 to thebed 1. The operator may grasp the handle of the lever 117, withdraw thelatch-pin 123 by ma ipulation of the springarm119 and shift the lever117 from one to the other of its operative positions. As shown in fulllines in Fig. 8. the lever 117 is in cut-before position. It is shown indotted lines in cutafter position.

There is connected to the master control lever 117, a link 1 :30 whichis connected to a lever 131, Fig. 3, fulcrumed at 132 on the standard 2and having its rearward end 133 bent at right angles to underhang thecutter-starting push-bar 134 which is pivoted at 135 to the arm (34 ofthe three-armed clamp-closing lever. This push-bar is the same inconstruction and function as that disclosed in said. Allen Patent No.1,548,815. hen permitted to rest upon the rearwardly disposed angularextension 38 of the cutterclutch controlling lever 38, under theinfluence of the spring 136, as is the case when the lever 131 is incut-first position, as shown in Fig. 16, the push-bar 134 is free forits tooth 137 to drop down behind the lever-arm 38 on the clamp-closingmovement of the three-armed-levcr 63, G4, 65 and push the lever-arm 3Srearwardly on the return movement-of the three-armed lever, thusstarting the buttonhole cutting mechanism immediately atter thework-clamps are closed. lVhen the master control lever is shifted tocut-after position the push-bar 134 is lifted to dotted line position,Fig. 8, by the action of the link 130 and lever 131, so that such bar134 will reciprocate idly upon the actuation of the clamp-closing lever63, 64, 65.

Mounted on the rapid-feed starting rockshaft 51 is an arm 138 on whichis slidably mounted a follower-tooth 139 connected by the link 140 tothe master control lever 117. lVhen the lever 117 is in cut-firstposition (full-lines, Fig. 8) the tooth 139 is within range of thetripping-point 141 on the driven cutter-clutch disk 90, whereby, as thecuttershaft 87 is completing its single revolution, the shaft 51 isrocked to start the rapid-feed mechanism. Vhen the master control leveris in cut-after position, the tooth 139 is withdrawn to dotted lineposition, Fig. 8, where it is out of range of the tooth 141.

The rapid feed-control rock-shaft 51 also has fixed thereto an arm 142to which is pivoted at 143, Fig. 17, a latch-lever 144 having a tailpiece 145 which is yieldingly held against the stop-pin 146 on the lever142 by the spring 147, in which position (dotted lines, Fig. 17) thelatch-lever 144 is within range of the actuating pin 148 on thedownwardly extending arm 65 of the three-armed clamp-closing lever. Inthis position of the latch-lever 144, which is known as the outafterposition, the pin 148 snaps past the latch-lever 144 on the first orclamp-closing movement of the three-armed clamp-closing lever anddepresses the latch-lever 144 and rocks the lever 142 to start therapid-feed mechanism on the return impulse of the clamp-closing lever.Vhen the tooth 139 is in full-line or cut-first position, an angle piece149 Fig. 11, secured to said tooth 139, is in engagement with the pin150 secured to the latch-lever 144 and is holding the latter inout-first position (full lines, Fig. 17) out of range of the pin 148.When the tooth 139 is shifted out of range of its actuator-tooth 141,the latch-lever 144 is permitted to oc cupy its dotted-line position,Fig. 17, within range of the pin 148.

It will thus be understood that two means are provided for starting therapid-feed mechanism to rapidly shift the work-clamp from initial orbuttonhole-cutting position to sewing position. One of these mechanismsis actuated by the buttonhole-cutting mechanism and the other by theclamp-closing mechanism, and when one of these mechanisms is active, theother is inactive, and vice-versa.

When the work-clamp reaches sewing position the rapid-feed mechanism isthrown out of action by the tripping point 57, Fig. 10, on the patternwheel 17. At the same time the cam rise 22 on the pattern wheel tiltsthe stop-motion lever 10 to running position, thus starting the sewingmechanism. At the completion of the sewing operation the calm shoulder24 passes the follower 23 and allows the spring 16 to restore thestop-motion lever 10 to stopping position. As the stopping tooth 13 iselevated by the cam rise 14" it operates through the lateral extension151, Fig. 1, to tilt the lever 152 and draw downwardly the latch 153 thenose of which snaps under the rear end of the arm 154 fast to therapid-feed starting rock-shaft 51. l/Vhen the tooth 13 drops into thestop-notch 14 in the stopping cam 14, the latch 153 is elevated andraises the arm 154,.thus starting the rapid-feed mechanism which shiftsthe work-clamp rapidly back to starting or buttonhole cutting position.

Pivotally mounted at the rearward end of the travelling work-clamp, onthe screw 155 is a bar 156 which extends rearwardly alongside thestandard 2 and passes loosely through a hole 157 in the bar 158. The bar158 is connected by a screw 159 to the arm 160 of a bell-crank-leverfulcrumed at 161 on the standard 2. The other arm 162 of thebellcrank-lever extends over and rests upon the push bar 134, being heldyieldingly thereupon by the spring 163 which is connected to the bar158.

The bar 156 is formed with a longitudinally disposed rib 164 whichenters a circumferential groove 165 in the hub of the clampopening andunspreading cam 166 which is slidably mounted on the cutter shaft 87;be-

where it may rotate idly without striking the follower lever 98. \Vhenthe lever 117 is shifted to cut-after position the cam 166 is shifted todotted line position, Fig. 14, where it may actuate the follower 98 andeffect the opening and unspreading of the work-clamp.

The bar 156 also has secured to it a cam or tooth 17 0 which, when themaster lever 117 occupies cut-first position, occupies full-.

line position, Fig. 13, where it wipes past the latch-lever 171 on thelever arm 98 on the rapid forward shift of the work-clamp from initialto sewing position. On the return rapid shift of the work-clamp, the cam170 engages the latch-lever 171 and rocks the lever 98, 97, thus openingand unspreading the work-clamp. It will be observed that two means areprovided for opening and unspreading the work-clamp and that when one ofsuch means is active the other is idle, and vice-versa.

One means for starting the buttonhole cutting mechanism (prior tosewing) has already been described. Another means is provided forstarting the buttonhole cutting mechanism (after sewing). Such meanscomprises a tooth 172 on the vertical gear 28. Just prior to the secondstopping of the rapidfeed mechanism, the tooth 172 engages and 9 rocksthe lever 173 which is, pivoted at 174 on the bracket 175. Pivoted at176 on the lever 173 is a bell-crank-lever 177, 178, the upper end ofthe arm 178 of which is forked to form a aw 179 embracing the downwardly extending tail 180 of the cutter-clutch controlling lever 88.

The master control lever 117 is formed with a cam-slot 181 which isentered by a follower screw 182 passing through a vertical guide-slot183, Fig. 18, in the fixed plate 184, and into the block 185 fixed tothe slidepin 186 mounted in the fixed guide 187. The arm 177 of thebell-crank-lever 177, 178 is yieldingly held against the lower end ofthe pin 186 by the spring 188. When the lever 117 is in cut-firstposition, the pin 186 is depressed, and holds the jaw 17 9 of the lever178 to the left, Fig. 20, of the tail 180 of the cutter-clutchcontrolling lever, so that the lever 173 will swing idly about the pivotpin 174 under the influence of the tooth 17 2. When the lever 117 isshifted to cut-after position, the pin'186 is elevated and the jaw 179shifted to the right, Fig. 20, to embrace the tail piece 180 ofthecutter-clutch controlling lever, whereby the cutting mechanism willbe tripped into action at the close of the rapid-feed subsequent tosewing.

lVhen the starting rod 74 is pulled downwardly by the operator inpressing upon the starting button 72, it is detained in itsdownwardposition by the latch 189, Fig. 19, which has a notch 190 adapted toembrace the screw 191 fixed to the rod 74. Thisprevents reactuation ofthe clamp-closing mechanism during the operation of the subsequentlytimed mechanisms. When the lever 17 3 is tilted by the tooth 17 2, thearm 178 engages the hooked extremity 192 of the latch 189, Fig. 19, andswings the latch inwardly, releasing the rod 7a which rises to startingposition under the influence of the spring 193.

The needle thread tension device 194 has the usual release pin 195 whichis actuated by the lever 190 fulcrumcd at 197 on the bracket 197. Thelower end of the lever 196 is shifted outwardly to release the tensionby the camblock 198 fixed upon and adjustable lengthwise of the rod 199which is secured at 200 to the travelling work-clamp. The rod 199 isguided in its endwise movements by the fixed bracket 201. The cam-block198 is timed to release the tension early in the rapid feed of theworkrlamp, subsequent to sewing. It is sometimes desirable to releasethe tension when the sewing reaches the end of a buttonhole, oppositethe beginning end and for this purpose a second block 202 is secured tothe rod 199. The block 202 has mounted thereon for vertical slidingmovement into and out of range of the lower end of the lever 196, acam-plate 203. \Vhen the cam-plate 203 is in full-line position, Fig. 2,it does not engage the tension release lever 196. Then moved upwardly todot-ted line position, Fig. 2, it serves to release the tension when thesewing reaches the end of the buttonhole opposite the beginning end.

The machine is provided with mechanism, such as disclosed in the AllenPatent No. 1,504,300, of Aug. 12, 1924, for locking the clutch-devicefor the button hole cutting mechanism against accidental operationduring a predetermined period of the operation 01" the machine. Thismechanism comprises the cam 204 which actuates the follower arm 205 faston the rock-shaft 200 to which is fixed the arm 207 connected by thelink 208 to the bell-crank-lever 209, 210. The lever arm 210 cooperateswith the push-bar 13 1 and cutter-clutch controlling arm 88 in the samemanner disclosed in said Allen Patent No. 1,504,306.

The sequence of operations will he briefly traced for each of the twosettings of the master control lever 117. \Vhen such lever is set incut-first position, a push upon the starting button 72 trips theclamp-closing and spreading mechanism into operation. This mechanismoperates through the push bar 134 to start the buttonhole cuttingmechanism. The buttonhole cutting mechanism operates through thecam-tooth 141 and follower 139 to start the rapid-feed mechanism. Therapid-feed mechanism acts through the pattern-cam 17 to start the stitchforming and sewing feed mechanisms which are in turn stopped by theaction of the cam shoulder 21 on the pattern-cam 17. The action of thetooth 13 on the stop-motion lever 10 starts the rapid-feed mechanism toreturn the workclamp to initial position, during which return the tooth170 elevates the lever arm 171 to open and unspread the work-clamp.

When the master control lever is set in cut-after position, as before, apush upon the starting button 72, trips the clamp-closing and spreadingmechanism into operation. This mechanism now operates through the pin148 to depress the lever-arm 14-2 and start the rapidifeed mechanism.The rapid-feed mechanism, as before, starts the stitch-forming andsewing-feed mechanisms, which are stopped by the action of thecam-shoulder 24 on the pattern-cam 17. The action of the tooth 13 on thestop-motion lever 10, as before, starts the rapid-teed mechanism toreturn the work-clamp to initial or buttonhole cutting position. Therapid-teed mechanism now acts through the tooth 172 on the gear 28 totilt the lever 17 3 and start the buttonhole cutting mechanism and thebuttonhole cutting mechanism acts through the cam 166 to open andunspread the work-clamp.

Having thus set forth the nature of the invention what I claim hereinis 1. In a buttonhole sewing machine, in combination, stitch-formingmechanism, buttonhole cutting mechanism, control means for varying thesequence of operations of said mechanisms, clamp closing mechanism,clamp-opening mechanism, and means connected with said control means forinsuring the invariable opening of the work-clamp subsequent to thestitching and cutting operations.

2. In a buttonhole sewing machine, in combination, stitch-formingmechanism, buttonhole cutting mechanism, control means for varying thesequence of operations of said mechanisms, clamp-spreading mechanism,clamp-unspreading mechanism, and means connected with said control meansfor insuring the invariable unspreading of the workclamp subsequent tothe stitching and cutting operations.

3. In .a buttonhole sewing machine, in combination, stitch-formingmechanism, buttonhole cutting mechanism, control means for varying thesequence of operations of said mechanisms, clan'ip-closing and spreadingmechanism, clamp-opening and -unspreading mechanism, and means connectedwith said control means for insuring the invariable opening andunspreading oi the work-clamp subsequent to the stitching and cuttingoperations.

4. In a buttonhole sewing macnine, in combination. stitcluformingmechanism, buttonhole cutting mechanism. control means for varying thesequence of operations of said mechanisms, a work-clamp, a feed'wheeland connections for relatively moving the stitchtorming mechanism andwork-clamp during the sewing and into and out of sewing relation, meansincluding a continuously running drive-shaft and rapid-teed-clutchdevice for rapidly driving the teedwheel with a continuous motion duringthe relative shift of the stitch-forming mechanism and wor clamp intoand out of sewing relation, and rapid-teed-clutch controlling meansconnected with said first mentioned control-means for insuring theinvariable operation of the rapid-teed mechanism immediately prior tothe operation of the stitch-forming mechanism, regardless of the time ofoperation of the buttonhole cutting mechanism.

5. In a buttonhole sewing machine, in combination, a work-clamp,clamp-closing means, buttonhole cutting mechanism including acutter-shaft, clan'ip-opening mechanism, a device movably mounted on thecutter-shaft for actuating the clamp-opening mechanism, a second devicemovably mounted on the work-clamp for actuating the clamp-openingmechanism, and control means for so moving said devices, that when oneis in position to actuate the clamp-opening mechanism the other isineffective, and vice-versa.

6. In a buttonhole sewing machine, buttonhole cutting mechanismincluding a cutter-shaft, a cam keyed to rotate with and slidelengthwise of said shaft, a travelling work-clamp, a lever tulcrumed onsaid workclainp and having a sliding engagement with said cam, andclamp-opening mechanism arranged to be actuated by said cam in one position on the cutter-shaft, said cam being ineffective in anotherposition on said shaft.

7. in a buttonhole sewing machine, abuttonhole cutting mechanismincluding a cutter-shaft, a cam keyed to rotate with and slidelengthwise of said shaft, a cylindrical hub on said cam having aperipheral groove, a travelling work-clamp, a cam-controlling leverpivoted on said work-clamp and having a rib engaging said groove, andclampopening meohanism arranged to be actuated by said cam. in oneposition of the latter on the cutter-shaft, said cam being ineffectivein another position on said shaft.

8. In a buttonhole sewing machine, a workclainp, clamp-openingmechanism, a buttonhole cutter-shaft, and an actuating element on saidshaft movable relatively to the latter into and out of position toactuate the clampopening mechanism.

9. In a buttonhole sewing machine, a traveliing work-clamp,clamp-opening mechanism, a buttonhole cutter-shaft, actuating elementson said cutter-shaft and work-clamp respectively movable into and out ofposition to actuate the clamp-opening mechanism, and means connected tosaid elements to move one out of operative position when the other ismoved into operative position and viceversa.

10. In a buttonhole sewing machine, a buttonhole cutter shaft,arapid-feed starting rock-shaft, a cam on the cutter-shaft, an arm fixedon said rock-shaft, a cam-follower slidably carried by said arm, and acontrol lever connected to slide said cam-f0llower on said arm into andout of range of said cam.

11. In a huttonhole sewing machine, a travelling work-clamp,clamp-opening mecha- HlSR'l mounted independently of the Wor:- clamp, anactuating element on said workclamp, and control means for moving saidactuating element relatively to the workclamp into and out of a positionoperative to actuate the clamp-opening mechanism.

In testimony whereof, I have signed my name to this specification.

EDWARD B. ALLEN.

